1. Technical Field
This invention relates to acoustics, and more particularly, to a system that enhances the perceptual quality of sound by reducing interfering noise.
2. Related Art
Many hands-free communication devices acquire, assimilate, and transfer a voice signal. Voice signals pass from one system to another through a communication medium. In some systems, including those used in vehicles, the clarity of a voice signal does not depend on the quality of the communication system or the quality of the communication medium. When noise occurs near a source or a receiver, distortion may interfere with the voice signal, destroy information, and in some instances, masks the voice signal so that it cannot be recognized.
Noise may come from many sources. In a vehicle, noise may be created by the engine, the road, the tires, or by the surrounding environment. When rain falls onto a vehicle it produces noise that may be heard across a broad frequency spectrum. Some aspects of this noise are predictable, while others are random.
Some systems attempt to counteract the effects of rain noise by insulating vehicles with a variety of sound-suppressing and dampening materials. While these materials are effective in reducing some noises, the materials also absorb desired signals and do not block the rain noise that may mask a portion of the audio spectrum. Another problem with some speech enhancement systems is that of detecting rain noise. Yet another problem with some speech enhancement systems is that they do not easily adapt to other communication systems.
Therefore there is a need for a system that counteracts the noise associated with water striking a surface across a varying frequency range.